A Preliminary Study On The Clinical Value Of CtDNA In The Diagnosis Of Ovarian Cancer

Objective: By detecting the chromosomal imbalance of circulating tumor DNA(ctDNA)in patients with different pathological types of ovarian malignancy and benign ovarian tumors,and comparing with the healthy control group,the plasma results in the tumor group were compared with the chromosomal imbalance in the corresponding tumor tissues.To explore whether ctDNA can provide a certain clinical value for preoperative diagnosis of ovarian cancer.Materials and methods: We selected 28 ovarian malignancies,36 patients with benign ovarian tumors,and 4 borderline ovaries treated from January 1,2016 to December 31,2017 in the gynecological center of Qingdao City Hospital.Related clinical data of cancer patients.At the same time,34 healthy women who had a physical examination at a municipal hospital in Qingdao during the same period were selected for venous blood as a control group.All patients received 8 ml of venous blood before surgery.After plasma was extracted,second-generation whole genome sequencing(WGS)method was used to determine chromosomal imbalance in ctDNA.Ovarian tumor specimens were collected during surgery.The same method was used for sequencing.Finally,biological information was analyzed.The ctDNA test results were assigned using the Cscore model.The chromosomal imbalance of ctDNA was compared between the malignant tumor group and the benign tumor group and the healthy control group.The consistency of the chromosomal imbalance between the ctDNA and the tissue DNA in the malignant tumor group was compared.The Cscore distribution of the tumor groups in different pathological types was analyzed,and the diagnosis of the malignant tumor group and the healthy control group was plotted.ROC curve,and ROC curve for differential diagnosis with benign tumor group.Results: 82.14%(23/28)of the malignant group detected a significant chromosome imbalance and was not limited to one chromosome,especially for high-grade serous ovarian cancer(HGSC),the positive rate of detection was 100%(18/18);borderline tumors There were 0-3 unequal chromosome imbalances;in the benign tumor group,1-2 chromosome abnormalities were detected in 4 cases;no chromosome imbalance was detected in the healthy group.By comparing the results of the ct DNA and tissue DNA tests in the malignant tumor group,a high degree of consistency between the two was suggested.According to pathological types of all tumors,Cscore comparison showed that the HGSC group Cscore was significantly higher than other groups.By Cscore positive sequencing,the malignant tumor group and healthy control group can be clearly distinguished,and the highest score of 10 cases are HGSC.The receiver operating characteristic curve(ROC)was plotted using the Cscore value and the area under the curve AUC was calculated to evaluate the diagnostic performance of the model.The HGSC was compared with the healthy group and the AUC was 1.000.The AUC was 0.8929 for all malignant tumors and healthy controls.The AUC was 0.8906 for the malignant tumor + borderline tumor group and the healthy group.In the differential diagnosis of benign and malignant ovarian tumors,if no distinction is made between histological subtypes,the AUC is 0.8700 for all malignant tumor samples compared with the benign group;if the malignant tumors only collect HGSC samples and benign tumor samples are compared,the AUC is 0.9880.Conclusions: 1.The chromosomal imbalance of ctDNA in ovarian cancer samples is severe,especially for high-grade serous ovarian malignancy(HGSC).This phenomenon is more prominent.2.The chromosomal imbalance between ctDNA and tumor DNA in patients with malignant tumors is highly consistent,indicating that ctDNA is derived from tumor tissues and carries genetic aberrations consistent with tumor tissue and may become a marker of malignant ovarian tumors.In this study,a screening model,Cscore score,was used to diagnose and differentially diagnose ovarian malignancies.The relative ideal AUC was obtained,suggesting that ctDNA may have certain clinical value in the diagnosis and differential diagnosis of ovarian malignancy.,still need further in-depth study.